The South Luzon Expressway (SLEX), signed as E2 of the Philippine expressway network and R-3 of the Metro Manila arterial road network, is a controlled-access highway that connects Metro Manila to the provinces in the Calabarzon, Mimaropa and Bicol Region on the island of Luzon in the Philippines. The expressway has a length of , traveling from its northern terminus at the Magallanes Interchange in Makati to its southern terminus at Santo Tomas, Batangas, connecting it to the Southern Tagalog Arterial Road (STAR Tollway). A portion of the expressway from the Magallanes Interchange to the Calamba Exit is part of Asian Highway 26 of the Asian highway network. It will be the longest expressway in the Philippines starting with the completion of Toll Road 4 surpassing the Subic–Clark–Tarlac Expressway (SCTEX) as well as providing a gateway to Visayas upon the completion of Toll Road 5.
The expressway also serves as a major utility corridor, carrying various high voltage overhead power lines and an oil pipeline. Notable power lines using the expressway's right of way for most or part of their route are the Sucat–Paco–Araneta–Balintawak transmission line, and the Biñan–Calamba and Calamba–Bay lines. The Magallanes–Alabang section of the expressway was also used to carry the Batangas–Pandacan oil pipeline. It is also one of the four expressways serving as the airplanes' northbound airway of domestic flights leading to Ninoy Aquino International Airport (NAIA) coming from Visayas and Mindanao along with STAR Tollway, Manila–Cavite Expressway (CAVITEX), and Metro Manila Skyway.
The expressway was built in 1969 to develop areas adjacent to Metro Manila, particularly the south. The original route spanning from Magallanes, Makati, to Alabang, Muntinlupa, was extended to Laguna in 1978. In 1995, the Magallanes–Alabang section became part of the Skyway System's at-grade section. Rehabilitation efforts on the expressway followed, lasting from 2006 to 2009.
Additionally, it is connected to the Southern Tagalog Arterial Road in Batangas since the second quarter of 2008 when the Toll Road 3 project (Calamba–Santo Tomas) reached the said expressway. The connection started construction in 2007 concurrent to the 3-year 2006–2009 rehabilitation of existing portions of the expressway until Calamba, Laguna, inaugurated on June 15, 2010, and opened to the traffic six months after its inauguration on December 15, 2010. Operations were transferred from Philippine National Construction Corporation (PNCC) to the South Luzon Tollways Corporation (SLTC) and Manila Toll Expressway Systems (MATES) on May 2, 2010.
Route description
The South Luzon Expressway cuts southwards from Metro Manila up to the provinces in Calabarzon. The expressway consists of two sections: the Skyway At-Grade segment, which runs underneath the Skyway from Magallanes Interchange in Makati to Alabang Exit in Muntinlupa, and the South Luzon Tollway (SLT) segment, also called the Alabang–Calamba–Santo Tomas Expressway (ACTEX), from Alabang to Santo Tomas, Batangas. Skyway At-Grade operations are held jointly by the Skyway Operations and Maintenance Corporation (SOMCO) and SMC Skyway Corporation (formerly Citra Metro Manila Tollways Corporation), while the South Luzon Tollway segment of SLEX is held by SMC SLEX, Inc. (formerly South Luzon Tollway Corporation), a concessionaire operated by Manila Toll Expressway Systems, Inc. (MATES) and a joint venture of the Philippine National Construction Corporation and the San Miguel Corporation-backed PT Citra Marga Nusaphala Persada Tbk group of Indonesia. SLT/ACTEX is further divided into three phases: SLEX Toll Road 1 (TR1): Alabang Viaduct in Muntinlupa SLEX Toll Road 2 (TR2): Filinvest Exit to Calamba Exit SLEX Toll Road 3 (TR3): Calamba Exit to SLEX-STAR Tollway boundary signages
The South Luzon Expressway starts as the physical extension of Osmeña Highway past the Magallanes Interchange, where it also meets Circumferential Road 4, EDSA. The expressway runs through , spanning the cities of Makati, Pasay, Taguig, Parañaque, and Muntinlupa in Metro Manila and the provinces of Cavite, Laguna, and Batangas. From its northern terminus at Magallanes Interchange, the expressway follows a straight path southeast in parallel to the PNR South Main Line until the Bicutan Exit, where it slightly bends to the south towards the Alabang Exit. Two service roads run on either side of the expressway from Sales Interchange to Alabang Exit, namely: West Service Road and East Service Road. Bicycle lanes are also present on the outermost lane of the toll-free northern section of the expressway, between the Magallanes and Sales Interchanges.
At the Alabang Exit, SLEX ascends to the Alabang Viaduct, a , eight-lane viaduct over the Manila South Road through Alabang, Muntinlupa. After its descent at Filinvest Exit, SLEX mostly parallels the Manila South Road in Muntinlupa and northwestern Laguna, passing through the Susana Heights Exit connecting it to the Muntinlupa–Cavite Expressway. It continues as a straight roadway lined with billboards and passing through residential and industrial areas. Past the San Pedro Exit, the expressway then curves and ascends past the Petron and Caltex service areas. Past Santa Rosa Exit, SLEX narrows with guard rails as the median divider. At the Calamba Exit, the Pan-Philippine Highway concurrency ends as it leaves the expressway towards the west as Maharlika Highway. Past such exit, the expressway further narrows without exits and with bridges built with wide shoulders to accommodate future widening. It follows a curved route paralleling the Pan-Philippine Highway (Maharlika Highway) from Calamba to Santo Tomas, Batangas. It then meets its future interchange with SLEX Toll Road 4 (TR4), which will extend it up to Lucena and eventually to Matnog, Sorsogon, via SLEX Toll Road 5 (TR5).
The expressway curves after an interchange leading to SLEX TR4 and TR5 as it enters Santo Tomas before it ends at the SLEX-STAR boundary signages at kilometer 57.4 after LISP Underpass and before Santo Tomas southbound exit and entrance (the interchange's northbound entrance from Pan-Philippine Highway is within the SLEX jurisdiction while the southbound is under STAR Tollway due to it being located after the said signages and part of STAR's construction) where the road continues south towards Batangas City through the latter.
History Planning and construction
The South Luzon Expressway was originally built during the 1960s as the Manila South Diversion Road, South Superhighway, or Manila South Expressway as newer roads used to travel from and to Manila. Located then in the province of Rizal, the original stretch of the expressway, spanning approximately from EDSA (Highway 54) in Magallanes, Makati to Alabang Exit in Muntinlupa, was constructed beginning in 1967 and was completed on December 16, 1969. It is the second roadway project completed by the Philippine National Construction Corporation, after North Luzon Expressway.
Later, the expressway was extended by another from Alabang up to Calamba, Laguna through the Manila South Expressway Extension project. It included the Alabang Viaduct in Alabang. Construction on the extension kicked off in 1974. The extension was completed and inaugurated by President Ferdinand Marcos on May 4, 1978, and was opened to public use a few weeks later. The name of this highway, as it is now commonly referred to, significantly reduces travel time from Alabang in Metro Manila to Calamba, Laguna, by over 50 percent, decreasing the journey from one hour to approximately 20 minutes. The construction of this expressway incurred a cost of .
This Alabang to Calamba segment originally had four lanes and traverses multiple municipalities in Cavite and Laguna before reaching Calamba. It included four interchanges, two viaducts, eleven twin bridges, nineteen overpasses, and six underpasses, with a total bridge superstructure length of . The widths of the bridges ranged from two to six lanes. Notably, the Alabang Viaduct stands out as the most remarkable structure, originally having six traffic lanes along its entire length of , making it the longest six-lane viaduct in the country at that time. Marubeni was the contractor for the extension project.
In 1982, South Superhighway from Magallanes to Calamba was renamed to Dr. Jose P. Rizal Highway, after the Philippine national hero Dr. José Rizal, who hailed from Laguna. This renaming was brought about by Batas Pambansa Blg. 264. In 1989, it was renamed to President Sergio Osmeña Sr. Highway, after the Commonwealth President Sergio Osmeña, by virtue of Republic Act No. 6760. The act was amended through Republic Act No. 7625 in 1992 to rename its portion in Laguna from kilometer 28.387 in San Pedro southwards to Dr. Jose P. Rizal Highway.
In 1995, the rehabilitation of the portion of SLEX from Magallanes to Alabang began as part of South Metro Manila Skyway Project Stage 1 that also includes the construction of the elevated Skyway above it up to Bicutan area. Thus, the Alabang Exit, which was also the expressway's former southern terminus, was designated as the concession boundary as PNCC decided to split SLEX into two concessions – the section from Magallanes to Alabang is made part of the Skyway System as the Skyway At-Grade, while the remaining section from Alabang southwards retains the South Luzon Expressway concession branding.
Expansion and rehabilitation
In 1977, President Marcos signed a decree proposing to extend the expressway to Lucena, Quezon. The PNCC proposal involved a three-stage extension for the expressway: beginning with a stretch to Santo Tomas, followed by a section to Tiaong, and concluding with a segment to Lucena. This project would have resulted in a total length of .
In 1996, PNCC entered into a joint venture with Hong Kong-based Hopewell Holdings to modernize and extend the expressway. Due to financial difficulties, Hopewell partnered with Crown Equities Inc. to form a joint venture, Hopewell Crown Infrastructure Inc. (HCII). HCII suggests extending the expressway through a joint venture from Calamba to Santo Tomas, covering approximately , and continuing on to Pagbilao for a total distance of . However, the deal with PNCC was terminated in 2005. The company was negotiating potential ventures with Egis of France, Leighton of Australia, Cise of Spain, MTD Capital of Malaysia, American company Transcore, and SNC Lavalin (now AtkinsRéalis) of Canada prior to Hopewell's departure. MTD and its subsidiary, MTD Equity, agreed to buy out HCII shares and rights from Crown Equities.
On February 1, 2006, a new agreement was signed between MTD and PNCC to rehabilitate, extend, and operate the expressway. Rehabilitation work started in May of that year, with heavy traffic brought by construction work. Prior to its rehabilitation, the South Luzon Expressway section from Alabang to Calamba was mostly an expressway with a grass median and two lanes per direction.
The widening of the Alabang Viaduct from three to four lanes per direction, a phase known as the SLEX Toll Road 1, was completed on December 11, 2008. Rehabilitation work on SLEX Toll Road 2 was finished in June 2009, resulting in the expansion of the Alabang–Santa Rosa section to eight lanes (four lanes per direction), similar to an American Interstate Highway, and the Santa Rosa–Calamba section to six lanes (three lanes per direction). Toll Roads 1 and 2 both involved the rehabilitation and modernization of existing Alabang–Calamba section of the expressway from 2006 to 2009.